Topic 6 Flashcards
What are retroviruses?
viruses that integrate their genome into the host genome and have a +ssRNA genome
How do retroviruses integrate their genome into the host genome?
-ssRNA is injected into genome and RdRP turns it into +ssDNA. The +ssDNA is equivalent to mRNA and the reverse transcriptase enzyme makes the +ssRNA into -ssDNA. Then the host DNA polymerase uses the ssDNA to generate dsDNA which will be joined into the host genome
What is the function of reverse transcriptase?
transcribes +ssRNA to -ssDNA
What is the function of RNA-dependent RNA polymerase?
transcribes +ssRNA to -ssRNA and vise versa
What is an isohedral phage and give an example?
a symmetrical virus that has repeated proteins that form triangular shapes enclosed in a capsid; example - herpes
What is a helical phage and give an example?
an asymmetrical virus that injects it’s genome into a host cell; example - T4 bacteriophage
What is a filamentous phage and give an example?
a symmetrical virus that consists of a long tube of genome capsid monomers; example - ebola
What is the difference between a prophase, temperate phage and a provirus?
a temperate phage is a virus following the lysogenic life cycle, a prophage is an integrated virus in a bacterial genome, and a provirus is an integrated virus in a eukaryotic genome
What is the biotechnological application of the reverse transcriptase enzyme?
it can be used in DNA cloning for RNA genomes
What is a virion?
a virus particle
What are viroids?
naked RNA viruses
What are prions?
proteins that can cause diseases
How does the Baltimore classify viruses?
Based on how they produce mRNA
What are the anti-phage defences that bacteria carry?
genetic resistance, restriction endonucleases, and CRISPR
